Some followers of the Kyron Horman case have wondered aloud in online message boards whether anyone was in the schoolroom when stepmom Terri Moulton Horman says she took the photo above.

The picture was posted on Horman's Facebook page just hours after she's told investigators she last saw Kyron on June 4. He's shown standing in front of his display at the school science fair, shortly before Horman says she saw Kyron walk off to his classroom as she left the building.

Besides quelling online speculation she may have doctored the photo, finding a witness in the room would aid law enforcement in the continued search for witnesses who saw Kyron or the stepmom at Skyline Elementary School the morning Kyron disappeared.

Now an alert reader sends along another photo from Horman's Facebook page. It shows Kyron's science-fair exhibit on the red-eyed tree frog. And a man appears to be standing in the background on the left. The circle and arrow come courtesy of the reader.

We've forwarded the photo to the Multnomah County Sheriff's Office along with questions about whether investigators were aware of the man in the background and, if so, whether they've questioned him. We have yet to hear back but will update this post when we do.

"I cannot speak to the specifics of the investigation," Lt. Mary Lindstrand, a spokeswoman for the sheriff's office, writes in an email. "[The sheriff's office] is following up on tips and information."